LMX2331UEVAL National Semiconductor, LMX2331UEVAL Datasheet - Page 45

• Manufacturer Part Number: LMX2331UEVAL
• Manufacturer: National Semiconductor

Specifications of LMX2331UEVAL

• Lead Free Status / Rohs Status: Not Compliant

Reg. Most Significant Bit
RF
Divide Ratio
N
Divide
Ratio
2.0 Programming Description
2.6.3 ID
The ID
2.6.4 TRI-STATE ID
The TRI-STATE ID
output state. This happens asynchronously with the change in the TRI-STATE ID
Furthermore, the TRI-STATE ID
powerdown mode.
2.7 RF N REGISTER
The RF N register contains the RF N_CNTRA, RF N_CNTRB, PRE RF, and PWDN RF control words. The RF N_CNTRA and RF
N_CNTRB control words are used to setup the programmable feedback divider. The detailed description and programming
information for each control word is discussed in the following sections.
2.7.1 RF N_CNTRA[6:0]
The RF N_CNTRA control word is used to setup the RF synthesizer’s A counter. The A counter is a 7-bit swallow counter used
in the programmable feedback divider. The RF N_CNTRA control word can be programmed to values ranging from 0 to 127.
2.7.2 RF N_CNTRB[10:0]
The RF N_CNTRB control word is used to setup the RF synthesizer’s B counter. The B counter is an 11-bit programmable binary
counter used in the programmable feedback divider. The RF N_CNTRB control word can be programmed to values ranging from
3 to 2047.
2047
TRI-STATE ID
3
4
•
PWDN
127
Control Bit
Control Bit
21
RF
0
1
•
o
ID
o
RF bit controls the RF synthesizer’s charge pump gain. Two current levels are available.
o
PRE
RF
20
RF
RF
10
0
0
1
•
o
19
RF
o
o
RF bit allows the charge pump to be switched between a normal operating mode and a high impedance
6
0
0
1
•
18
RF
9
0
0
1
•
Register Location
Register Location
17
RF Synthesizer Charge Pump Current Gain
RF Synthesizer Charge Pump TRI-STATE Current
RF Synthesizer Swallow Counter (A Counter)
RF Synthesizer Programmable Binary Counter (B Counter)
o
RF R[18]
RF R[19]
RF bit operates in conjuction with the PWDN RF bit to set a synchronous or an asynchronous
16
RF N_CNTRB[10:0]
8
0
0
1
•
5
0
0
1
•
15
14
7
0
0
1
•
13
SHIFT REGISTER BIT LOCATION
(Continued)
RF Charge Pump
Current Gain
RF Charge Pump
TRI-STATE Current
4
0
0
1
•
Data Field
12
Description
Description
6
0
0
1
•
RF N_CNTRB[10:0]
RF N_CNTRA[6:0]
11
45
10
5
0
0
1
•
3
0
0
1
•
9
RF Charge Pump
Normal Operation
4
0
0
1
•
8
o
RF bit.
0.95 mA
7
LOW
2
0
0
1
•
RF N_CNTRA[6:0]
0
0
3
0
0
1
•
6
5
Function
Function
RF N[9:19]
2
0
1
1
•
4
RF N[2:8]
1
0
0
1
•
RF Charge Pump
Output in High
Impedance State
RF R[18]
Least Significant Bit
RF R[19]
3
3.80 mA
1
1
0
1
•
HIGH
2
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1
1
Address
1
1
0
0
1
1
•
Field
0
1
0
1
•
0
1